CHAPTER XI 



SOME POSSIBLE, BUT IMPERFECTLY ESTABLISHED CASES OF 

 ARTHROPOD TRANSMISSION OF DISEASE 



Infantile Pakalysis or Acute Anterior Poliomyelitis 



The disease usually known in this country as infantile paralysis 

 or, more technically, as acute anterior poliomyelitis, is one which 

 has aroused much attention in recent years. 



The causative organism of infantile paralysis is unknown, but 

 it has been demonstrated that it belongs to the group of filterable 

 viruses. It gives rise to a general infection, producing characteristic 

 lesions in the central nervous system. The result of the injury to 

 the motor nerves is a more or less complete paralysis of the corres- 

 ponding muscle. This usually manifests itself in the legs and arms. 

 The fatal cases are usually the result of paralysis of the muscles 

 of respiration. Of the non-fatal cases about 60 per cent remain 

 permanently crippled in varying degrees. 



Though long known, it was not until about 1890 that it was 

 emphasized that the disease occurs in epidemic form. At this time 

 Medin reported his observations on an epidemic of forty-three cases 

 which occurred in and around Stockholm in 1887. Since then, 

 according to Frost ( 1 9 11 ) , epidemics have been observed ivith increas- 

 ing frequency in various parts of the world. The largest recorded 

 epidemics have been those in Vermont, 1894, 126 cases; Norway and 

 Sweden, 1905, about 1,500 cases; New York City, 1907, about 

 2,500 cases. Since 1907 many epidemics have been reported in the 

 United States, and especially in the Northern States east of the 

 Dakotas. In 1912 there were over 300 cases of the disease in Buffalo, 

 N. Y., with a mortality of somewhat over 11 per cent. 



In view of the sudden prominence and the alarming spread of 

 infantile paralysis, there have been many attempts to determine 

 the cause, and the manner in which the disease spreads and develops 

 in epidemic form. In the course of these studies, the question of 

 possible transmission by insects was naturally suggested. 



C. W. Howard and Clark (1912) presented the results of studies 

 in this phase of the subject. They dealt especially with the house- 

 fly, bedbug, head, and body lice, and mosquitoes. It was found 

 that the house-fly (Musca domestica) can carry the virus of poliomye- 

 litis in an active state for several days upon the surface of the body 



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